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1.
EClinicalMedicine ; 46: 101361, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35360148

ABSTRACT

Background: Exercise is important in type 2 diabetes (T2D) management. Focussing on Maori and Pacific people and those from deprived circumstances, the Diabetes Community Exercise Programme (DCEP) was developed to engage people with T2D in exercise. We report the evaluation of whether being offered DCEP (plus usual care) was more effective than usual care in improving glycaemic control at 1-year. Methods: A randomised, two-arm, parallel, open-label trial with blinding of outcome assessor and data analyst. Adults (age ≥35 years) with T2D recruited from two New Zealand (NZ) communities were randomised, using opaque sealed envelopes and stratified by centre with random block lengths, to DCEP or usual care. DCEP comprises twice-weekly, two-hour sessions of exercise and education over 12-weeks, followed by a twice-weekly maintenance exercise class. The primary outcome was between-group differences in mean changes of glycated haemoglobin (HbA1c) from baseline to 1-year follow-up with intention-to treat analysis. This trial is registered with the Australian NZ Clinical Trials Registry (ANZCTR): ACTRN12617001624370p and is closed to new participants. Findings: From 2018 - 2019, of 294 people screened, 165 (mean age 63·8, SD16·2 years, 56% female, 78·5% European, 14% Maori, 6% Pacific, 27% most deprived) were baseline evaluated, randomised, and analysed at study end (DCEP = 83, control = 82). Multimorbidity (≥2) and polypharmacy (>5 medications) were high (82%, 69%). We found no statistically significant between-groups differences in HbA1c (mmol/mol) change at 15 months (mean 3% higher in DCEP, 95% CI 2% lower to 8% higher, p = 0·23). Twelve-week intervention adherence was good (41% attended >80% available sessions). No adverse events were reported. Interpretation: DCEP was not effective in improving glycaemic control, possibly due to insufficient exercise intensity. Our attendance demonstrated DCEP's cultural accessibility. DCEP might be good to engage in exercise marginalised people with high Hb1Ac levels, multimorbidity, and high polypharmacy. Funding: Health Research Council of New Zealand.

3.
J Geophys Res Oceans ; 124(1): 403-431, 2019 Jan.
Article in English | MEDLINE | ID: mdl-31007997

ABSTRACT

Biogeochemical Argo floats, profiling to 2,000-m depth, are being deployed throughout the Southern Ocean by the Southern Ocean Carbon and Climate Observations and Modeling program (SOCCOM). The goal is 200 floats by 2020, to provide the first full set of annual cycles of carbon, oxygen, nitrate, and optical properties across multiple oceanographic regimes. Building from no prior coverage to a sparse array, deployments are based on prior knowledge of water mass properties, mean frontal locations, mean circulation and eddy variability, winds, air-sea heat/freshwater/carbon exchange, prior Argo trajectories, and float simulations in the Southern Ocean State Estimate and Hybrid Coordinate Ocean Model (HYCOM). Twelve floats deployed from the 2014-2015 Polarstern cruise from South Africa to Antarctica are used as a test case to evaluate the deployment strategy adopted for SOCCOM's 20 deployment cruises and 126 floats to date. After several years, these floats continue to represent the deployment zones targeted in advance: (1) Weddell Gyre sea ice zone, observing the Antarctic Slope Front, and a decadally-rare polynya over Maud Rise; (2) Antarctic Circumpolar Current (ACC) including the topographically steered Southern Zone chimney where upwelling carbon/nutrient-rich deep waters produce surprisingly large carbon dioxide outgassing; (3) Subantarctic and Subtropical zones between the ACC and Africa; and (4) Cape Basin. Argo floats and eddy-resolving HYCOM simulations were the best predictors of individual SOCCOM float pathways, with uncertainty after 2 years of order 1,000 km in the sea ice zone and more than double that in and north of the ACC.

4.
Acta Diabetol ; 53(6): 991-998, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27585938

ABSTRACT

AIMS: While there have been many outcome-focussed studies examining insulin pump therapy, only a few have looked at potential adverse events (AEs), with none examining the relationship between AEs and pump/infusion set type, ethnicity or socio-economic status. In addition, current data on the incidence and characteristics of pump-associated AEs are confined to one paediatric centre. We aimed to describe the incidence, characteristics and potential predictors of insulin pump-associated AEs in New Zealand adults and children with T1DM. METHODS: We approached adults and families of children with T1DM on insulin pumps in four main New Zealand centres. Participants completed a questionnaire examining pump-related issues they had experienced in the preceding 12 months. RESULTS: Response rate was 64 % with 174 of 270 eligible people participating in the study. 84 % of subjects reported one or more AEs, with an overall AE incidence of 3.42 per person/year (95 % CI 3.14, 3.73). An event serious enough to require a hospital presentation occurred in 9.8 %, all but one reporting high ketones or diabetic ketoacidosis (DKA). Set/site problems were the AE most commonly reported (by 53 % of respondents), followed by cutaneous complications (43 %) and pump malfunction (38 %). Few predictors of AEs (of any type) were found; however, a negative binomial regression model found that a longer duration of pumping (p = 0.018) and age <18 years (p = 0.043) were both associated with fewer AEs (all types combined). CONCLUSIONS: Insulin pump-associated AEs are very common. However, few variables are predictive of them with no relationships seen with glycaemic control, socio-economic status, pump manufacturer or infusion set type. Based on these findings, AEs should be anticipated in both adults and children, with anticipatory patient education and training recommended for their successful and safe use.


Subject(s)
Diabetes Mellitus, Type 1 , Diabetic Ketoacidosis , Equipment Failure/statistics & numerical data , Insulin Infusion Systems , Insulin , Adolescent , Adult , Blood Glucose/analysis , Child , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/epidemiology , Diabetic Ketoacidosis/epidemiology , Diabetic Ketoacidosis/etiology , Female , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/adverse effects , Incidence , Insulin/administration & dosage , Insulin/adverse effects , Insulin Infusion Systems/adverse effects , Insulin Infusion Systems/statistics & numerical data , Male , Middle Aged , New Zealand/epidemiology , Social Class , Time Factors
5.
Meat Sci ; 119: 110-7, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27155799

ABSTRACT

The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63days) on beef quality characteristics and consumer sensory perception of biceps femoris (BF) and semimembranosus (SM) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values of the BF and SM. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the SM, while no difference was observed for the BF. Consumer panel results revealed that longer aging periods increased (P<0.05) acceptability of the SM, tenderness of both muscles, and tended to increase (P=0.07) juiciness of the SM. Our results show that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of both muscles and overall acceptability of the SM.


Subject(s)
Food Handling , Food Quality , Red Meat , Taste , Adolescent , Adult , Animals , Cattle , Color , Consumer Behavior , Cooking , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Muscle, Skeletal , Time Factors , Young Adult
6.
Appetite ; 96: 160-165, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26403933

ABSTRACT

BACKGROUND: While there have been considerable advances in the medical management of type 1 diabetes mellitus (T1DM), for many, glycaemic control remains substandard. Nutrition and eating behaviour are important additional factors to consider with regards to T1DM management and outcomes. Intuitive eating is one such factor, and has not previously been investigated in T1DM. With this in mind, we undertook a study examining the relationship between intuitive eating and glycaemic control in adolescents with T1DM. METHODS: A case-control study of adolescents with established T1DM, and age/sex matched controls was conducted. Demographic information, the Intuitive Eating Scale (IES), and HbA1c were collected. Statistical analysis was undertaken to explore associations between the IES and HbA1c as a marker of glycaemic control. RESULTS: Data on 38 adolescents with T1DM, and 39 age/sex matched controls were obtained. Those with T1DM had significantly lower (by 0.5 SD) IES scores compared to controls (p = 0.009). Higher values of both total IES and the Eating for physical rather than emotional reasons subscale were associated with lower HbA1c: HbA1c 22% lower/whole unit increase in total IES mean score, HbA1c 11% lower/whole unit increase in Eating for physical rather than emotional reasons mean score, p = 0.017 and p = 0.009 respectively. CONCLUSION: In adolescents with T1DM, there appears to be a strong association between intuitive eating, in particular the effect of emotion on eating, and glycaemic control. In addition, those with T1DM have lower scores for their intuitive eating behaviour compared to controls. Emotional eating could be a future target for screening and potentially intervening in those with T1DM, as part of a wider treatment package to improve glycaemic control. Continuing efforts are needed to fully understand the important dynamics of diabetes, adolescence, diet, emotion, and how these factors affect long term outcomes in those with T1DM.


Subject(s)
Blood Glucose/metabolism , Feeding Behavior/psychology , Adolescent , Body Mass Index , Case-Control Studies , Diabetes Mellitus, Type 1/diet therapy , Female , Humans , Male
7.
Meat Sci ; 110: 32-9, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26172241

ABSTRACT

The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63 days) on beef quality characteristics and consumer sensory perception of gluteus medius (GM) and longissimus lumborum (LL) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values for both muscles and L* values for the LL. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the LL, while no difference was observed for the GM. Consumer panel results demonstrated that longer aging periods increased (P<0.05) tenderness of both muscles. Our results indicate that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of beef loin muscles.


Subject(s)
Color , Consumer Behavior , Food Handling/methods , Red Meat/analysis , Stress, Mechanical , Adolescent , Adult , Animals , Cattle , Female , Humans , Male , Middle Aged , Muscle, Skeletal , Taste , Time Factors , Young Adult
8.
Health Promot J Austr ; 26(1): 70-73, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25785361

ABSTRACT

ISSUE ADDRESSED: School gardens are a potentially important health promotion tool, allowing the growth and consumption of fruit and vegetables to be embedded within the students' educational experience. This study aimed to investigate the implementation of edible gardens in New Zealand (NZ) primary and secondary schools. METHODS: A questionnaire mailed to principals from a randomly selected sample of 764 NZ schools included questions on whether or not the school had a garden and, if so, what produce was grown; how long the garden had been in place; how harvested crops were distributed; and curriculum integration. RESULTS: Among 491 responding schools (64.3% response rate), 52.9% currently had an edible garden - with most gardens started in the previous two years. Vegetables, herbs and tree fruit were commonly grown. Gardens were integrated into curriculum subjects, cooking lessons, recipes and messages promoting increased fruit and vegetable consumption. CONCLUSIONS: Edible gardens were common within NZ schools, though often relatively new, and were used for teaching in a variety of curriculum areas. SO WHAT?: Given the current popularity of school gardens, there are opportunities to deliver health promotion messages regarding consumption of fruit and vegetables, and for these to be reinforced by real life experience growing and preparing healthy food.


Subject(s)
Agriculture/methods , Fruit , Health Promotion/methods , Schools , Vegetables , Humans , New Zealand , Surveys and Questionnaires
9.
Skin Res Technol ; 21(4): 459-65, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25773121

ABSTRACT

BACKGROUND: Skin color is related to human health outcomes, including the risks of skin cancer and vitamin D insufficiency. Self-perceptions of skin color may influence health behaviours, including the adoption of practices protective against harmful solar ultraviolet radiation levels. Misperception of personal risk may have negative health implications. The aim of this study is to determine whether Munsell(®) color chart assessments align with child self-reported skin color. METHODS: Two-trained investigators, with assessed color acuity, visually classified student inner upper arm constitutive skin color. The Munsell(®) classifications obtained were converted to Individual Typology Angle (ITA) values and respective Del Bino skin color categories after spectrocolorimeter measurements based on published values/data. As part of a written questionnaire on sun protection knowledge, attitudes, and behaviours, self-completed in class time, students classified their end of winter skin color. Student self-reports were compared with the ITA-based Del Bino classifications. A total of 477 New Zealand primary students attending 27 randomly selected schools from five geographic regions. The main measures were self-reported skin color and visually observed skin color. RESULTS: A monotonic association was observed between the distribution of spectrophotometer ITA scores obtained for Munsell(®) tiles and child self-reports of skin color, providing some evidence for the validity of self-report among New Zealand primary school children, although the lighter colored ITA defined groups were most numerous in this study sample. Statistically significant differences in ITA scores were found by ethnicity, self-reported skin color, and geographic residence (P < 0.001). Certain Munsell(®) color tiles were frequently selected as providing a best match to skin color. CONCLUSION: Assessment using Munsell(®) color charts was simple, inexpensive, and practical for field use and acceptable to children. The results suggest that this method may prove useful for making comparisons with other studies using visual tools to assess skin color. Alignment between the ITA distribution derived from the Munsell(®) assessment and child skin color self-reports could probably be improved, particularly with the addition of another 'light'/'white' color category in the self-report instrument.


Subject(s)
Color Perception Tests/methods , Color Perception Tests/standards , Color Perception/physiology , Colorimetry/methods , Colorimetry/standards , Skin Pigmentation/physiology , Child , Diagnostic Self Evaluation , Female , Humans , Male , New Zealand , Observer Variation , Physical Examination , Reference Values , Reproducibility of Results , Self Report , Sensitivity and Specificity
10.
Obes Sci Pract ; 1(2): 67-77, 2015 12.
Article in English | MEDLINE | ID: mdl-27774250

ABSTRACT

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD), defined as excessive fat accumulation in hepatocytes when no other pathologic causes are present, is an increasingly common obesity-related disorder. We sought to describe the prevalence of elevated liver enzymes, a marker of liver damage, among New Zealand adults, and high-risk subgroups including those with an elevated body mass index and those with pre-diabetes or diabetes, to gain a better understanding of the burden of liver disease. METHODS: A total of 4,721 New Zealanders aged 15+ years participated in a nationally representative nutrition survey. Liver enzymes, alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT) were measured in serum. Results were available for 3,035 participants, of whom 10.8% were Maori and 4.5% Pacific. RESULTS: Overall, the prevalence of elevated ALT and elevated GGT was 13.1% (95% confidence interval [CI]: 11.2 - 15.0) and 13.7% (95% CI: 12.0 - 15.4), respectively. Odds ratios for an elevated ALT or GGT markedly increased with increasing body mass index. Men with obesity had the highest elevated ALT prevalence (28.5%; 95% CI: 21.7-35.4), and women with diabetes had the highest elevated GGT prevalence (36.5%; 95% CI: 26.0-47.0). Adding alcohol consumption categories to each of the adjusted models did not meaningfully change any results, although for women, heavy alcohol consumption was associated with an elevated GGT (overall p = 0.03). CONCLUSIONS: Obesity-related liver disease is likely to increasingly burden the New Zealand health sector and contribute to health disparities unless effective obesity treatment and prevention measures are given high priority. © 2015 The Authors. Obesity Science & Practice published by John Wiley & Sons Ltd, World Obesity and The Obesity Society.

11.
J Skin Cancer ; 2014: 135473, 2014.
Article in English | MEDLINE | ID: mdl-24660064

ABSTRACT

Background. Sun-tanning perceptions are monitored to identify changes and help refine targeting of skin cancer prevention messages. Aim. To investigate associations between perceptions of sun-tanning and demographic factors among a New Zealand urban population, 1994-2006. Methods. A telephone survey series was conducted during summer in 1994, 1997, 1999/2000, 2002/2003, and 2005/2006. Demographic and personal information (sex, age group, skin sun-sensitivity, and self-defined ethnicity) obtained from 6,195 respondents, 50.2% female, 15-69 years, was investigated in relation to six sun-tanning related statements. A total "positive perceptions of tanning" (ProTan) score was also calculated. Regression analyses modelled each component and the ProTan score against survey year and respondent characteristics. Results. Statistically significantly higher ProTan scores were found for age group (strong reverse dose-response effect), male sex, residence (highest in Auckland), ethnicity (highest among Europeans), and sun sensitivity (an n-shaped association). There was no statistically significant change in total ProTan scores from baseline. Conclusions. The development, pretesting, and evaluation of messages for those groups most likely to endorse ProTan statements should be considered for the New Zealand skin cancer prevention program. To achieve and embed significant change, mass media campaigns may require greater intensity and reinforcement with sustained contextual support for settings-based behavioural change.

12.
J Clin Neurosci ; 19(3): 423-7, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22249018

ABSTRACT

The diagnostic value and reliability of selected neurological clinical tests was studied in control subjects with normal neuroimaging (n=42), and subjects with a focal brain lesion (n=38). The items were studied by two examiners blinded to group membership and using standardized protocols, and subsequently by a neurologist who was not blinded to diagnosis. The positive likelihood ratios ranged from 1.06 (pronator drift) to 22.11 (single leg stance with eyes open, while the negative likelihood ratios ranged from 0.47 (tandem gait) to 0.97 (pupil symmetry). Three items (single leg stance - eyes closed - firm surface; single leg stance - eyes open - foam surface; and tandem gait) successfully distinguished between the two groups (odds ratio p<0.05). The inter-rater reliability was generally poor, with only tandem gait showing excellent agreement (kappa [K]=0.92). Tandem gait was the only item to show noteworthy agreement (K=0.93) between the examiners and the neurologist. The tests varied considerably in their ability to detect radiologically demonstrated structural brain lesions, and several items were poorly reproducible, questioning their value as part of a routine neurological examination.


Subject(s)
Nervous System Diseases/diagnosis , Neurologic Examination/statistics & numerical data , Adolescent , Adult , Aged , Data Interpretation, Statistical , Gait/physiology , Headache/diagnosis , Headache/etiology , Humans , Middle Aged , Neuroimaging , Observer Variation , Physical Therapy Modalities , Postural Balance/physiology , Pronation/physiology , Psychomotor Performance/physiology , Pupil/physiology , Reproducibility of Results , Sample Size , Speech Production Measurement , Young Adult
13.
Eur J Clin Nutr ; 65(1): 117-24, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20877394

ABSTRACT

BACKGROUND/OBJECTIVES: Diets high in nuts reduce cholesterol, probably due to their favorable lipid profile and other bioactive substances. However, the physical form of the nut may be important as the cell wall of intact nuts may limit the hypocholesterolemic effect of nuts by reducing lipid bioavailability. Therefore, we investigated the effects on blood lipids of incorporating three different forms of hazelnuts (ground, sliced and whole) into the usual diet. SUBJECTS/METHODS: In a randomized crossover study with three phases, 48 mildly hypercholesterolemic participants were asked to consume 30 g of ground, sliced or whole hazelnuts for 4 weeks. Body weight, plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triacylglycerol (TAG), apolipoprotein (apo) A1, apo B100 and α-tocopherol were measured at baseline and at the end of each dietary phase. RESULTS: There were no significant differences in any outcome variable between the different forms of nuts (all P ≥ 0.159). However, compared with baseline, mean values at the end of each hazelnut intervention were significantly higher for HDL-C (P = 0.023) and α-tocopherol (P = 0.005), and significantly lower for TC (P < 0.001), LDL-C (P < 0.001), TC:HDL-C ratio (P <0 .001), apo B100 (P = 0.002) and apo B100:apo A1 ratio (P < 0.001), with no significant difference in body weight (P = 0.813). CONCLUSIONS: The ingestion of three different forms of hazelnuts equally improved the lipoprotein profile and α-tocopherol concentrations in mildly hypercholesterolemic individuals. Hazelnuts can therefore be incorporated into the usual diet as a means of reducing cardiovascular disease risk.


Subject(s)
Cholesterol, HDL/blood , Cholesterol, LDL/blood , Corylus , Hypercholesterolemia/diet therapy , Triglycerides/blood , alpha-Tocopherol/blood , Adult , Apolipoprotein A-I/blood , Apolipoprotein B-100/blood , Body Weight , Cross-Over Studies , Diet , Female , Humans , Linear Models , Male , Middle Aged
14.
Aust N Z J Surg ; 64(10): 695-8, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7945068

ABSTRACT

Fifty-six patients with possible appendicitis were evaluated clinically and by ultrasound. Ultrasound examination visualized the appendix in 18 of the patients evaluated and showed another pathology in six others. It was useful when the clinical picture was not clear (25 patients) as it showed an inflamed appendix in 10 patients. This was of particular value when there was another critical illness making clinical evaluation difficult (three patients), and for the diagnosis of other unsuspected pathological conditions (six patients). It did not affect the line of management when the clinical picture was clear enough to diagnose or exclude acute appendicitis.


Subject(s)
Appendicitis/diagnostic imaging , Acute Disease , Adolescent , Age Factors , Appendicitis/epidemiology , Appendicitis/surgery , Child , Child, Preschool , Critical Illness , Diagnosis, Differential , Evaluation Studies as Topic , Female , Humans , Infant , Infant, Newborn , Male , Physical Examination , Sensitivity and Specificity , Ultrasonography
15.
Oral Microbiol Immunol ; 6(5): 310-2, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1820571

ABSTRACT

The predominant cultivable flora in pericoronitis was investigated by culturing pus from affected sites in 20 patients. Twenty colonies were picked at random from non-selective plates and identified using conventional biochemical and physiological tests, analysis of metabolic end-products by gas chromatography and protein profile analysis. The most frequently isolated organisms were Prevotella (Bacteroides) intermedia, Peptostreptococcus micros, Veillonella species, Fusobacterium nucleatum and Streptococcus mitis. Porphyromonas (Bacteroides) gingivalis was not isolated and asaccharolytic Eubacterium species were virtually absent. The predominant cultivable microflora in pericoronitis was found to be highly anaerobic in nature and superficially similar to that found in chronic periodontitis, although proposed marker organisms of severe periodontitis were absent.


Subject(s)
Pericoronitis/microbiology , Adolescent , Adult , Bacteria, Anaerobic/isolation & purification , Female , Humans , Male
17.
Br J Oral Maxillofac Surg ; 29(2): 97-9, 1991 Apr.
Article in English | MEDLINE | ID: mdl-2049364

ABSTRACT

A case of idiopathic blepharospasm-oromandibular dystonia (Meige's syndrome) is reported, presenting as chronic bilateral dislocation of the temporomandibular joints. The nature of the syndrome is discussed, together with the difficulties in diagnosis and management.


Subject(s)
Joint Dislocations/diagnosis , Meige Syndrome/diagnosis , Temporomandibular Joint Disorders/diagnosis , Aged , Chronic Disease , Diagnosis, Differential , Humans , Male , Meige Syndrome/pathology
18.
Oral Surg Oral Med Oral Pathol ; 70(1): 86-9, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2196507

ABSTRACT

Occasional reports have described the presence of melanin in various odontogenic lesions. A case of melanin pigmentation in an adenomatoid odontogenic tumor is described.


Subject(s)
Maxillary Neoplasms/pathology , Melanins , Odontogenic Tumors/pathology , Adolescent , Epithelium/pathology , Humans , Male
19.
Ann Trop Med Parasitol ; 77(6): 569-82, 1983 Dec.
Article in English | MEDLINE | ID: mdl-6660964

ABSTRACT

The development of local skin reactions following bites by tsetse flies (Glossina morsitans) infected with Trypanosoma congolense was observed in normal rabbits, in rabbits with concurrent infections with T. congolense and in rabbits challenged after immunization by infection and treatment. Local reactions developed in normal rabbits within seven days of fly bite and were resolved by approximately 19 days after infection. In rabbits with concurrent infections no typical local reactions developed when they were bitten by infected tsetse flies. By allowing a single infected fly to bite a rabbit sequentially it was established that suppression of reaction development to homologous secondary challenge occurred within three to eight days of primary infection. Suppression of reaction development also occurred in infected rabbits challenged with an antigenically heterologous trypanosome stock within 14 to 18 days of primary infection, suggesting that reaction suppression is not associated with the specific immune response. It was also found that no neutralizing antibodies had developed against the parasites used for secondary infection by 28 days post-challenge. Rabbits were immunized by allowing an infected tsetse fly to feed on a rabbit and seven days later, when local reactions had appeared, treating it with homidium chloride. All rabbits challenged within 75 days of immunization by a tsetse fly infected with a homologous trypanosome stock resisted re-infection and some animals were immune up to 300 days after treatment. In most of the immunized animals specific neutralizing antibody activity against homologous parasites was low, suggesting that local expression of immunity in the skin might be more important in resistance to cyclically transmitted infections than serum antibodies. No local reactions developed on immune rabbits challenged with a homologous trypanosome stock but immunized rabbits challenged with heterologous trypanosome stocks developed typical local reactions.


Subject(s)
Insect Bites and Stings/immunology , Trypanosomiasis, African/immunology , Tsetse Flies , Animals , Antibodies/analysis , Cricetinae , Immunization , Immunocompetence , Skin/immunology , Trypanosoma congolense/immunology
20.
Parasite Immunol ; 5(6): 547-56, 1983 Nov.
Article in English | MEDLINE | ID: mdl-6657293

ABSTRACT

Rabbits were infected with two clones of antigenically distinct stocks of Trypanosoma congolense transmitted through Glossina morsitans. Local skin reaction development and the appearance of neutralizing antibodies were followed in animals infected with one or other of the trypanosome stocks, with both stocks simultaneously or with both stocks consecutively. There was little difference in local skin reaction development on rabbits infected with a single stock or with both stocks simultaneously but, in rabbits exposed to a heterologous stock 14 or 21 days after a primary infection reactions were reduced in size or completely absent. Neutralizing antibodies against metacyclic-derived trypanosomes were detected 21 days after infection in animals infected with a single trypanosome stock and, in rabbits infected with both stocks simultaneously, antibodies against each stock were also detected 21 to 28 days after infection. In rabbits challenged 14 or 21 days after primary infection the appearance of trypanocidal antibodies against the stock used for challenge was delayed from 28 to 49 days.


Subject(s)
Antibodies/analysis , Rabbits/immunology , Trypanosoma congolense/immunology , Trypanosomiasis, African/immunology , Animals , Antibody Formation , Cattle , Cattle Diseases/immunology , Female , Immune Tolerance , Insect Vectors/parasitology , Male , Mice , Neutralization Tests/methods , Trypanosomiasis, African/parasitology , Trypanosomiasis, African/transmission , Tsetse Flies/parasitology
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